THE SENSE OF SMELL IN BIRDS 633 
doves, two young crows, some common fowls, turkey vultures, 
and a paroquet were used as subjects for the tests. As these 
experiments proved to be worthless, it appeared to be necessary 
to develop more elaborate methods for distinguishing possible 
responses to olfactory stimuli, and a labyrinth in which the bird 
=A 
Text fig. A Labyrinth without cover; d, entrance to chamber A, 0, liter wash- 
bottle; 6’, small bottle which contained the odorous material and was located 
here when the food box was in the position which is indicated in fig. C; ¢. glass tube 
which connected odor bottle with the wash bottle; f, tube leading to two small 
bottle connections; d, entrance to main enclosure from cage. 
would have the opportunity of finding its food was devised. This 
apparatus, shown in figs. A and B, included a central area five 
feet wide and ten inches high, with four accessory chambers, 
each of which opened into the central enclosure at the middle 
of aside. The chambers were ten inches square and so arranged 
that a bird in the central enclosure could not see food placed at 
Jabs hier O. 
